Protective edge for easy opening container

ABSTRACT

An easy opening container in which the end closure is formed with annular fold bands. A weakening line to define a removable panel portion is formed in the central panel slightly outboard of the folded smooth edge of the annular fold bands so that the folded edge protects the user from the sharp edges after removal of the removable panel portion. This disclosure also relates to a method for forming the above described easy opening end closure wherein the weakening line is formed in the end panel prior to complete formation of the fold band.

United States Patent 1 3,696,961 Hulk, Jr. 51 Oct. 10, 1972 [54]PROTECTIVE EDGE FOR EASY 3,434,623 3/1969 Cookson ..220/54 OPENINGCONTAINER 3,447,713 6/1969 Stec ..220/54 [72] Inventor: Albert J HolkJr. Frankfort In. 3,527,377 9/1970 Colby et al. ..220/54 [73] Assignee:Continental Can Company, Inc., Primary Examiner-George T. Hall New York,NY. Attorney-fret! P. Kostka, Joseph E. Kerwin and Wil- 221 Filed: Oct.20, 1970 [211 App]. No.: 82,260 [57] ABSTRACT ti An easy openingcontainer in which the end closure is f S App on Data formed withannular fold bands. A weakening line to Commuatlon-lI1-Pa1't 0f 815,043,P" define a removable panel portion is formed in the cen- 10, 1969,abandoned.

US. Cl. ..220/54, 220/906 Int. Cl. ..B65d 17/20 Field of Search..220/54, 27, 48, 90.6

References Cited UNITED STATES PATENTS 2/ 1967 Taylor ..220/54 tralpanel slightly outboard of the folded smooth edge of the annular foldbands so that the folded edge protects the user from the sharp edgesafter removal of the removable panel portion.

This disclosure also relates to a method for forming the above describedeasy opening end closure wherein the weakening line is formed in the endpanel prior to complete formation of the fold band.

6 Claims, 12 Drawing Figures l3 5 I0 28 lfl 24 3,: L

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ATT'Y PROTECTIVE EDGE FOR EASY OPENING CONTAINER This application is acontinuation-in-part of US. Pat. application Ser. No. 815,043 filed Apr.10, 1969 now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to easyopening containers and more particularly to a new and improved easyopening container of the full panel opening type and to the method offorming the same.

Full opening containers of the type to which the present inventionrelates include an end closure of which the end panel is formed with aweakening line located closely adjacent to the chuck wall. The weakeningline is formed by scoring and defines a removable panel section to whichthere is attached a pull tab. The pull tab is mounted so that uponinitial lifting thereof the nose of the tab penetrates the weakeningline to initiate the severance of the removable panel section from theend panel. Thereafter, the pull tab is pulled upwardly so that theremainder of the weakening line is ruptured and the removable panelportion separated from the remainder of the panel substantially in theform of a disc.

The opening thus formed in the end closure is bounded by a horizontalledge which terminates in a sharp raw edge caused by the severance ofthe removable panel portion therefrom. This sharp edge is somewhatobjectionable because it may cause injury by cutting the users hand orotherwise damage an article which may be inserted through the opening.

The edge on the removable portion is also sharp and is a hazard ifcarelessly discarded.

SUMMARY OF THE INVENTION By the present invention, it is proposed toprovide a full opening easy opening container having an end closureconstructed and arranged so that the raw edge about the horizontal ledgeis protected after severance of the removable panel portion.

It is also proposed to provide a full opening easy opening container inwhich the edge on the removable panel is protected.

A further embodiment is proposed wherein both the edge on the ledgeremaining on the container and the edge on the removable panel portionare protected.

It is a further object to construct an easy opening end so as to inhibitthe flexure of the panel portion adjacent the score line and thereby tofacilitate the separation of the removable panel portion.

It is still a further object to provide a new and novel method forfonning a full easy opening end closure constructed in the mannerspecified in the immediately foregoing objects.

In one form of the invention, the foregoing objects are accomplishedgenerally by an end closure having an annular horizontal folded panel inthe form of a band disposed adjacent to the end closure chuck wall andin which a weakening line is formed in the panel so that the folded edgeof the band provides a smooth surface which bounds the opening after theseparation of the removable panel portion along the weakening line tothereby provide a protective edge.

In another form of the invention the panel of the end closure isprovided with a stacked pair of folded bands of which one folded bandpresents a smooth edge protecting the cut edge on the ledge extendingfrom the chuck wall and the other folded band presents a folded edgeprotecting the cut edge of the removable panel portion.

In still another form of the invention a folded panel portion isprovided on either one of the ledge or removable panel portions and aplastic shield is adhered to the unfolded portion so as to extend beyondthe cut edge resulting from removal of the removable panel portion.

In carrying out the method of constructing the end closure of thepresent invention, the annular fold panel is formed in stages and theweakening line is formed by scoring prior to the final fold step.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspectiveview of an easy opening container incorporating the easy openingstructure of the present invention;

FIG. 2 is a top plan view of an easy opening container end closure witha portion of the panel being broken away to show underlying details ofthe annular fold band;

FIG. 3 is a fragmentary cross-sectional view of the container takengenerally along the lines 3-3 of FIG. 2 and showing the rupture of thepanel along the weakening line upon initial lifting of the pull tab;

FIGS. 4, 5, 6 and 7 are greatly enlarged fragmentary sectional viewsshowing sequentially how dies are employed to form the annular foldedportion and in FIG. 6 showing the scoring die performing the weakeningline prior to the final folding of the annular band by the final foldingdies shown in FIG 7;

FIG. 8 is a fragmentary cross-sectional view of another form of theinvention showing a plastic band disposed for separation with theremovable panel por tion to provide a protective edge;

FIG. 9 is a fragmentary sectional view of a third embodiment of theinvention showing the folded annular panel formed on the removable panelportion;

FIG. 10 is a fragmentary cross-sectional view of a fourth embodiment ofthe invention showing annular fold panels formed on both the ledge andthe removal panel portion of the end closure; and

FIG. 11 is a fragmentary cross-sectional view of a fifth embodiment ofthe invention in which the fold panels are arranged somewhat differentlyfrom that shown in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingparticularly to FIGS. 1 to 3. There is shown a sheet metal can 10 havinga tubular sheet metal body 11. Secured to the upper end of the metalbody 11 as by means of a double seam 13 is an easy opening end closure12 embodying the structure of the present invention. The lower end, notshown, of the body 11 is also provided with an end closure which isfixed thereto by a double seam.

The container body or can body 11 if formed from a metal blank which isformed into tubular configuration and its marginal edges bonded into alongitudinally extending side seam.

The upper end closure 12 may be formed from either tin plate tin freesteel, black plate or aluminum and includes a substantially horizontallyextending central panel 14 which extends over and covers the open end ofthe can body. The central panel is recessed within the body 11 so thatthe horizontal plane in which it lies is below the level of the loweredge of the double seam 13 as shown in FIG. 3. At its periphery, thepanel 14 is formed with a chuck wall 16 which terminates in a horizontalflange l7 and a curled end 18 as shown in FIGS. 4-7. The horizontalflange 17 and curled end are double seamed into the can body 11.

In accordance with the present invention, the central panel 14 is bentback upon itself outwardly away from the center and again inwardlytoward the center of the body 11 to form an annular fold 19 adjacent tothe chuck wall 16. The fold band 19 thus comprises a double fold or twolayers 21 and 22 which are disposed below the panel 14. It is to beparticularly noted that the fold provides a turned smooth or hemmed edge23 facing along the interior of the container. Moreover, the panelportion 14 superimposed over the annular fold 19 is in close proximityto the chuck wall 17 and extends substantially planar toward the centerof the container body 1 l.

Formed in the panel portion 14 inwardly of the turned edge 23 is aweakening line 24 along which a removable panel portion 26 is separatedfrom the panel. The weakening line 24 is formed by means of scoring orthe like as more fully to be described hereinafter. The weakening line24 extends substantially continuously about and substantially concentricwith the chuck wall 16. Disposed closely adjacent to the primaryweakening may be a second concentric score 25 which serves as ananti-fracture score to relieve the stresses in the weakening line.

Fixed to the removable panel portion 26, as by a rivet 27 which may beformed integral with the panel, is a pull tab 28. The pull tab 28 issubstantially rigid along the length thereof and is formed at one endwith a ring or finger grip portion 29 and the other end with apenetrating nose 3]. The nose 31 is disposed adjacent to or over theweakening line 24 so as to penetrate the latter upon initial upwardtilting of the pull tab 28. As shown, the pull tab 28 is tiltable aboutan attachment ear 32 defined by a lance formed in the tab body. Upontilting of the tab 28, the nose 31 is operative to initially sever theremovable panel portion along the weakening line 24 as shown in FIG. 3.It is to be noted that the weakening line 24 lies inwardly of and inclose proximity to the smooth hemmed edge 23 of the annular fold band 19so that upon downwardly movement into the severing position there is nointerference to resist the downwardly bending of the removable panelportion 26.

It is also to be noted that the annular band 19 tends to render the areain which the score line is located more rigid by reducing theflexibility of the relatively thin guage metal from which the endclosure 12 is made. This increased rigidity at the score line aids infacilitating the removal of the removable panel portion 26 becausedownward bending of the panel is resisted and thereby minimizes theamount of force which must be applied on the pull tab 28 to initiallysever the weakening line 24. Moreover, upon upward pulling of the pulltab 28 to separate the remainder of the removable panel 26 from thepanel 14 along the weakening line 24, the annular fold band also servesto resist upward bending and facilitates the further separation.

Referring now to FIGS. 4, 5, 6 and 7 illustrating the stations forforming the end panel closure 12 of the present invention, in FIG. 4there is illustrated the first station for forming the same. The endclosure 12 is initially in the form of a disc and is positioned betweena lower male die set 36 and an upper female die set 37. The lower maledie set 36 includes a drawing punch 38 which is received within an axialrecess 39 of a draw die 41 of the upper female die set 37.Concentrically disposed about the draw die 41 and the draw punch 38respectively is a lower flange forming member 42 and an upper flangeforming member 43. A forming punch 46 concentric with the upper flangeforming die 43 serves to form a downwardly depending lip 18a on theflange 17.

Initially, the flat disc is placed between the lower male die set 36 andthe upper female die set 37. As the upper and lower dies close together,the flange forming members 42 and 43 clamp the disc therebetween alongthe marginal edge portions thereof. Thereafter, the lip forming memberor punch 46 may descend to form the depending lip 18a. The female die 41and draw punch 38 also close to form a hat section 14a which projectssubstantially above the flange 18. The hat-shaped section 14a includes ahorizontal top 14c which defines the central panel 14 and an upstandingflange 14b from which the annular fold band 19 is formed as more fullyto be explained hereinafter.

The partially formed end unit as formed in FIG. 4 is then transferred toa second station as shown in FIG. 5 wherein a second set of dies 47 and48 including an upper die member 49 in the form of a hammer and a lowerdie member 51 in the form of an anvil. Disposed concentrically about thehammer 49 and anvil 51 is a pair of clamping rings 52 and 53 which whenclosed clamp the chuck wall 16 adjacent the lower end hereof.Thereafter, the hammer 49 strikes the horizontal web 14c and forces thelatter downwardly into engagement with the anvil 51. This causes thevertical wall 14b of the hat section to be reformed into a partiallyloosely folded condition as shown, in the annular space provided betweenthe side wall of the anvil 51 and the upper ring clamp 52. It is to benoted that the horizontal wall or panel is then at substantially thesame level as the flange 17.

Thereafter, the second stage end closure .is transferred to a thirdstation as shown in FIG. 6 at which the previous reformed hat section14a is scored by a scoring die set including a scoring tool 54 and ananvil 56. The scoring tool 54 includes a primary scoring rib 57 and ananti-fracture scoring rib 58. The anti-fracture scoring rib 58 serves toreduce the stresses on the primary score and may be omitted if the metalfrom which the end closure is made is not subject to fracture causingstresses on the primary score at the primary score 24. For supportingthe partially folded end closure, there is provided a nesting block 59which accommodates and supports the chuck wall 16 therein. It is to benoted that the end closure is supported so that no further bendingoccurs during the scoring operation when the anvil 56 and scoring tool54 are closed. The scoring of the end closure 12 in this manner permitsan accurate control of the residual thickness of the weakening line 24.This control of the thickness is not possible if the scoring is formedafter the annular band 19 is formed because of the multiple thickness ofthe fold band structure 19. With a multiple thickness fold, it is notpossible to always maintain a consistent and exact thickness of the foldlayers 21 and 22 and the overlying panel 14 when the end closures aremade on a mass production basis.

The partially formed and scored end closure 12 is thereafter transferredto the fourth station for final bending as shown in FIG. 7. The fourthstation includes an upper die set including a hammer 61 and a lower dieset providing a nesting block 62 into which the partially formed andscored end closure 12 is positioned. The lower nest block 62 includes anannular groove 63 in which the fold 19 is received when the upper andlower die set are closed. As shown, the hammer and nesting blocks 61 and62, respectively are shaped so that upon closing the layers 21 and 22are guided to be received within the groove 63.

In connection with the final folding operation, it is to be noted thatthe partially and loosely folded vertical web 14b, makes it possible tocomplete the fold 19 into the nesting block 62 without causing afracture along the score or weakening line 24. This is of significance,because in the absence of, forming a partially folded side wall 14b tocomplete the fold at the second station it has been found impractical toform the weakening line 24 prior to forming the fold band 19.

Referring now to FIG. 8, there is shown a modified arrangement of thestructure shown in FIGS. 1-3. The central panel 14 is formed with acircumferential downwardly depressed head 33. The annular folded panelportion 19 is folded inboard and adjacent to the bead 33. The score line24 is located relative to the folded edge 23 in the same manner asdescribed heretofore in connection with FIGS. l3.

Attached to the underside of the removable panel portion 26 is a band 34of a pliable plastic such as plastisol. The plastisol band 34 is adheredby a suitable adhesive coating such as vinyl resin which may be appliedby spot coating on the removable panel portion The remainder of theunderside of the panel 14 including the fold portion 23 may be coatedwith a coating non-adherent to the plastisol as for example a thermosetting resin. The plastisol band 34 may be applied by spin lining sothat the fold edge 23 restricts the outward flow of the plastisol.

The removable panel portion 26 is separated from the panel similar tothe manner explained in connection with FIG. 1-3. When the removablepanel portion 26 is separated, the portion of the band 34 lying in the26 upon removal thereby to protect the cut edge from contact by theuser.

A third embodiment of the protective structure is shown in FIG. 9. Asshown, the panel 14 of the end closure 112 is formed with a fold band119 disposed a greater distance from the chuck wall 16 than the foldband 19 in the embodiment of FIGS. l-3. This permits a score line 122 tobe formed in the annular space between the chuck wall 16 and an innerfolded edge 124. The score line 124 is located such that upon severanceby a pull tab 125 in the manner described in connection with FIGS. 1-3,the folded edge projects outwardly of the severed edge of the sufficientamount to prevent free contact therewith. In this manner, the cut edgeof the removable panel portion 126 is protected.

If desired, the edge on the ledge 128 may be protected by a plastisolband 134. The plastisol band is adhered to the underside of the ledge118 as by a spot coating by a band of an adhesive such as a vinyl resincoating. The vinyl resin coating may be applied on an non-adherentcoating such as a thermo-setting resin coating covering the underside ofthe panel. The portion of band overlying the thermo-setting coating isnot adherent thereto so that upon severance of the removable panelportion 126, the band 134 remains adhered to and projects outwardly ofthe cut edge of the ledge 128.

Referring now to FIG. 10, there is shown a fourth embodiment of theinvention. The end closure 212 includes a central panel 214 which isformed with a pair of radially spaced annular fold panels 215 and 216.The panel 215 includes fold layers 217, 218 and 219. The fold layer 218is common to the fold panel 216 which also includes fold layers 220 and221. The fold layers 217 and 218 are connected by a folded edge 222 andthe fold layers 220 and 221 by a folded edge 223. Provided on the foldlayer 219 is a score line 224. The score line 224 is located so thatupon separation of the removable panel portion 225 defined by the scoreline 224, the raw or cut edges contiguous to the fold layers areprotected by the folded edges 222 and 223, respectively.

For removing the removable panel portion 225, there is provided a pulltab 227. The pull tab 227 is mounted in substantially the same manner asthe pull tab of FIGS. 1-3. The pull tab 227 includes a downwardlyprojecting nose 228 which overlies the score line 224. Upon tilting ofthe pull tab 227, the pull tab nose 228 severs the score line 224 andthe folded panel 228 is depressed downwardly past the folded edge 224.Thereafter, the pull tab 227 is pulled upwardly so that the removablepanel 225 is completely separated. In this matter, the fold panel 216 isremoved with the removable panel portion and fold panel 215 remainsattached to the container. The cut edge overlying the folded edge 224 isprotected thereby and the folded edge 223 protects the cut edge on theremovable panel portion 225.

Referring now to FIG. 11, there is shown another embodiment of theinvention differing from the embodiment of FIG. 10 by the fact thatannular folded panels 315 and 316 are folded toward the interior of thecontainer rather than the exterior. The folded panel 315 includes anouter layer 317, an intermediate layer 318 and a bottom layer 319. Thebottom layer 319 forms the upper layer of the folded panel 316.Underlying the layer 319 are fold layers 320 and 321. The fold layers317 and 318 are folded along afolded edge 322 while the fold layers 320and 321 are folded along the folded edge 323.

A score line 327 is formed in the panel 319 between the fold edges 322and 323. The score line 323 is severed by tilting of the pull tab 324 sothat a nose 325 engages the weakening line 327 so that the portion ofthe fold panel 316 adjacent thereto is depressed downwardly into thecontainer body. Thereafter, upward pulling of the pull tab 324 causesthe remainder of the removable panel portion 326 to be separated fromthe end closure.

It is to be noted that upon separation of the removable panel portionthat the folded edge 322 protects the cut edge of the score lineremaining on the end closure, while the folded edge 323 protects the cutedge on the removable panel portion 326.

Referring now to FIG. 12 there is shown a still further embodiment ofthe invention in which an end closure 410 has fold layers 411 and 412underlying a marginal panel 413 extending from the chuck wall 414. Thefold layers 411 and 412 define an annular fold panel 415. Connecting thefold layers 411 and 412 is a folded edge 416. Disposed closely to thefolded edge 416 on the panel portion 413 is a score line 417 whichdefines a removable panel portion 418. Mounted on the removable panelportion similar to the manner described in connection with the priorembodiments is a pull tab 419 having a nose 421. Upon tilting of thepull tab 419 the score line is severed and upward pulling thereaftercompletely separates the removable panel. When the removable panelportion 418 is completely separated, the folded edge 416 of the foldpanel 419 protects the cut edge bounding the portion 418.

If desired the cut edge on the ledge may be protected by a plastisolband (not shown) applied to the underside of the end closure so as toremain adhered to the end after removal of the removable panel portion.

What is claimed is:

1. An easy opening container comprising an end closure having a paneland an upstanding chuck wall, said panel being folded to provide adouble folded annular band, a weakening line formed in said paneldefining a removable panel portion and a panel ledge extending from saidchuck wall, said folded annular band having an inner periphery definedby a turned smooth edge, a pull tab fixed to said removable panelportion for separating said removable panel portion from said panelalong said weakening line, said weakening line being located so thatsaid folded annular band is disposed on said panel ledge after removalof said removable panel portion whereby said turned smooth edge providesa protective edge along the severed edge of said weakening line on saidpanel ledge, and a plastic band adhered to said panel for removal withsaid removable panel portion for providing a protective edge along thesevered edge of said weakening line on said removable panel portion.

2. An easy opening container comprising an end closure having a paneland an upstanding chuck wall, said panel being folded to provide adouble folded annular band, a weakeni line form din sai anel defremovable panei aortion and a panel l dge pro fi ng from said chuckwall, said folded annular band having a periphery defined by a turnedsmooth edge to provide a protective edge, a pull tab fixed to saidremovable panel portion for removing said removable panel portion fromsaid panel along said weakening line, said weakening line being locatedso that said folded annular band is disposed on said removable panelportion upon removal of said removable panel portion whereby said turnedsmooth edge provides a protective edge along the severed edge of saidweakening line on said removable panel portion.

3. The invention as defined in claim 1 wherein a plastic band is adheredto said panel so as to remain attached to said panel ledge after removalof said removable panel portion, said plastic band providing aprotective edge along the severed edge of said panel ledge after removalof said removable panel portion.

4. An easy opening container comprising an end closure having a paneland a chuck wall, said panel being folded to provide a stacked pair ofdouble folded annular bands having a fold band common to said pair, saiddouble folded annular bands each having a periphery defined by turnedsmooth edges, said turned smooth edges being located on opposite sidesof said common panel, a weakening line formed on said common fold paneldefining a removable panel portion and a panel ledge extending from saidchuck wall and located so that said respective turned smooth edgesprovide protective edges along the severed edge of said weakening lineon said removable panel portion and the severed edge on said panel ledgewhen said removal panel portion is removed from said panel, and a pulltab fixed to said removable panel portion for removing said removablepanel portion from said panel along said weakening line.

5. The invention as defined in claim 4 wherein said pair of double foldbands are stacked on the outer side of said panel.

6. The invention as defined in claim 4 wherein said pair of double foldbands are stacked on the underside of said panel.

1. An easy opening container comprising an end closure having a paneland an upstanding chuck wall, said panel being folded to provide adouble folded annular band, a weakening line formed in said paneldefining a removable panel portion and a panel ledge extending from saidchuck wall, said folded annular band having an inner periphery definedby a turned smooth edge, a pull tab fixed to said removable panelportion for separating said removable panel portion from said panelalong said weakening line, said weakening line being located so thatsaid folded annular band is disposed on said panel ledge after removalof said removable panel portion whereby said turned smooth edge providesa protective edge along the severed edge of said weakening line on saidpanel ledge, and a plastic band adhered to said panel for removal withsaid removable panel portion for providing a protective edge along thesevered edge of said weakening line on said removable panel portion. 2.An easy opening container comprising an end closure having a panel andan upstanding chuck wall, said panel being folded to provide a doublefolded annular band, a weakening line formed in said panel defining aremovable panel portion and a panel ledge projecting from said chuckwall, saiD folded annular band having a periphery defined by a turnedsmooth edge to provide a protective edge, a pull tab fixed to saidremovable panel portion for removing said removable panel portion fromsaid panel along said weakening line, said weakening line being locatedso that said folded annular band is disposed on said removable panelportion upon removal of said removable panel portion whereby said turnedsmooth edge provides a protective edge along the severed edge of saidweakening line on said removable panel portion.
 3. The invention asdefined in claim 1 wherein a plastic band is adhered to said panel so asto remain attached to said panel ledge after removal of said removablepanel portion, said plastic band providing a protective edge along thesevered edge of said panel ledge after removal of said removable panelportion.
 4. An easy opening container comprising an end closure having apanel and a chuck wall, said panel being folded to provide a stackedpair of double folded annular bands having a fold band common to saidpair, said double folded annular bands each having a periphery definedby turned smooth edges, said turned smooth edges being located onopposite sides of said common panel, a weakening line formed on saidcommon fold panel defining a removable panel portion and a panel ledgeextending from said chuck wall and located so that said respectiveturned smooth edges provide protective edges along the severed edge ofsaid weakening line on said removable panel portion and the severed edgeon said panel ledge when said removal panel portion is removed from saidpanel, and a pull tab fixed to said removable panel portion for removingsaid removable panel portion from said panel along said weakening line.5. The invention as defined in claim 4 wherein said pair of double foldbands are stacked on the outer side of said panel.
 6. The invention asdefined in claim 4 wherein said pair of double fold bands are stacked onthe underside of said panel.